https://wccftech.com/ios-15-keep-multiple-app-copies/

Though it took a long time for this option to be available for iPhone users, iOS 15 now allows multiple app copies to be placed on any part of the display and as many times as you want. This certainly looks like Apple took a page out of Android’s book since you can have multiple app copies running on Google’s mobile operating system too.

One reason why iOS 15 allows multiple app copies is thanks to its new Focus features. Depending on which Focus mode you are in at the time, you can disable home screen pages. This also means that you can set up different modes for when you are working and relaxing. For example, when you are in work mode, you can set it up to hide the app pages that have all your distraction-inducing apps in one place to maintain your concentration and productivity.